This application is presented on behalf of the Mouse Metabolic and Phenotyping Center (MMPC) network () and its Advisory Committee. The MMPC network groups five Centers (located at Case Western Reserve University, University of Cincinnati, University of Texas SouthWestern, University of Washington, Vanderbilt University, Yale University) and a Coordinating and Bioinformatics Unit (located at the Medical College of Georgia). The goal of this five-year project is to expand the educational and training activities of the MMPC network by organizing a series of courses and hand-on workshops on the use of isotopic techniques for metabolic investigations. Although the MMPC network was created to provide phenotyping testing in mice, it is integrated in the wider research and training activities of NIDDK, NHLBI and the NIH. Therefore, the scope of the planned courses and workshops on isotope technology will not be limited to investigations of mouse metabolism. The faculty who will run the courses and workshops have wide expertise in the use of isotopes for metabolic studies in animals and humans. They are also involved in the development of new isotopic, metabolomic and proteomic techniques which will allow major expansion of metabolic investigations conducted from the mouse to the bedside. This project builds on the teaching and training expertise of Dr Robert R. Wolfe, a member of the MMPC External Advisory Committee. Dr Wolfe has created in 1992, and taught eight times with colleagues, a course on the use of isotopes for metabolic studies. This course drew trainees from all over the United States. In October 2007, Dr Wolfe and MMPC faculty joined forces to teach a new version of the isotope course. This new course, which was very well received by about 80 trainees, is the template for the courses to be taught under the present application. In addition, we plan to conduct each year one specialized hand-on workshop in the laboratory of a member of the course faculty.